Nickel alloy composition



United States This invention relates to a novel alloy of nickel having unexpected and superior strength characteristics at elevat ed temperatures in the range of 2000" F. In a more particular aspect, this invention concerns itself with a nickel base alloy containing precipitated complex carhides.

The recent advent of high speed aircraft and missiles has created a need for materials which exhibit high strength and resistance to oxidative degradation at temperatures in the range of 2030" F. and above. Presently known alloys, often referred to as superalloys do not possess the necessary high temperature tensile strength required by engine liner material and back up material for the skin structure of re-entry and space vehicles.

Accordingly, it is the primary object of this invention to provide an improved nickel base alloy.

Another object of this invention is to provide a novel nickel base alloy that exhibits high strength and resistance to oxidative degradation at elevated temperatures in excess of 2000* F.

The novel features which are believed to be characteristic of the invention are set forth in the appended claims. However, the invention, both as to its organization and method of operation, together with further objects, advantages and features thereof, may be best understood by considering the following detailed explanation of a specific embodiment of the invention.

An alloy, in accordance with this invention, may con tain the following elements within the percentage ranges set forth in Table I.

The present invention is based on the discovery that an unexpected improvement in elevated temperature strength and oxidative resistance results from the addition of significant amounts of carbon. Apparently, the formation of complex carbides enhances the strength characteristics of the base alloy to a significant degree.

Example I discloses a preferred alloy within the range stated in Table I and having the following approximate analysis:

Example 1 Element: Percent Tungsten 17.75 Chromium 17.17 Tantalum 7.5 8

atent ice Percent Aluminum 4.16 Molybdenum 3 .50 Carbon 2.46 Columhium 1.07 Iron 0.93 Titanium 0.5 2 Silicon 0.16 Zirconium 0.09 Nickel Balance The alloys of this invention are particularly resistant to oxidation at temperatures of about 2000 F. in addition to their unex ected hot strength. Also, although the utility of these alloys has been emphasized with respect to their use as liner and back up material for skin structures of re-entry space vehicles, it is to be understood that the alloys may also be utilized for making valves, valve seats, castings and other structural elements. The alloys of this invention may be compounded or made up in any desired manner employing conventional alloying technrques.

Unless otherwise indicated, the term percent, as used in the instant specification and appended claims, refers to ercent by weight based on the total alloy weight.

Although the present invention has been described with reference to preferred embodiments, those skilled in the art will readily understand that various modifications and alterations thereof may be resorted to without departing from the spirit of the invention, and that all such modifications as fall Within the scope of the appended claims are intended to be included herein.

What is claimed is:

1. A nickel base alloy consisting essentially or the following composition:

2 A nickel base alloy consisting essentially of the following composition:

Percent Tungsten 17.75 Chromium 17.17 Tantalum 7.58 Aluminum 4.16 Molybdenum 350 Carbon 2.46 Columbium 1.07 Iron 0.93 Titanium 0.52 Silicon 0.16 Zirconium 0.09 Nickel Balance References Cited in the file of this patent UNITED STATES PATENTS Thielemann Aug. 9, 1960 Michael et a1 Apr. 9, 1963 

1. A NICKEL BASE ALLOY CONSISTING ESSENTIALLY OF THE FOLLOWING COMPOSITION: 